Water-resistant, polymeric titanium ester-impregnated wood and method of making same



United States Patent Ofice Patented June 12, 1956 WATER-RESISTANT, POLYMERIC TITANIUM ESTER-Ilt IPREGNATED WOOD AND METH- OD OF MAKING SAME Robert W. La Barge, Magnolia, N. 3., assignor to E. I. tlu Pontde Nemours and Company, Wiimington, Deb, a corporation of Delaware- No Drawing. Application May-'7', 1953, Serial No. 353,675

13 Claims. (Cl. 117-72) This invention relates to inhibition of water vapor transmission through rigid pervious media on which protective paints are normally applied. More particularly it is concerned with a protective coating system which when applied to the surface of pervious materials exhibits superior resistance to moisture-blistering.

, Moisture-blistering is one of the most prominent causes of failure of exterior house paints. Where a diiferential in atmospheric moisture conditions exists, a pervious barrier separating the two states of different moisture content serves as a membrane for transmission of water from the high level state to the state of lower level. This type of house paint failure. is most common in the colder climates where the interior atmosphere is maintained at a substantially higher temperature than the exterior atmospheric temperature for prolonged periods. As a consequence, moisture of the humid interior atmosphere condenses on the inside of the outer wall and migrates through the outer wall to the painted surface and forces the paint loose in the form of blisters. Water, in its capillary migration through a pervious medium, is capable of exertingtremendous pressure.

Wooden house siding is a typical pervious membrane capable of transmitting moisture when the moisture on. e

the inside of the house is at a higher level than that of the exterior atmosphere. The exteriorly applied paint is generally ineffectual in the inhibition of moisture transmission from an interior atmosphere condition of m ls,- ture content of higher level than that of the exterior atmosphere. Painting of both faces of the wooden membrane would be helpful in retarding the transmission of moisture under conditions of high moisture diflFerential but it is impractical in practice.

The need for a water vapor barrier is well recognized today and better quality building construction employs a substantially non-pervious water and water vapor barrier, such as asphalt impregnated sheet material or alu minum foil, between the unprotected inner surface of the outer wall and the atmosphere of high moisture level. Obviously, the barrier must be an integral part of the original structure to provide an adequate seal against moisture transmission.

Another conventional means for minimizing moistureblistering of house paint is to avoid a high. humidity differential such that approximately equilibrium moisture conditions exist between the interior atmosphere in contact with the unpainted innersurface of the outer wall Such pressure is sufficient to overcome the adhesive forces binding a paint I terior atmosphere is very cold it is practically impossible and the exterior atmosphere in contact with the painted to prevent condensation of moisture on the cold wall from a warm humid interior atmosphere by the use of mechanical means of moisture reduction.

Of the described means ofinhibiting moisture-blistering of house paints the vapor barrier provides a substantially impervious membrane supplementing the pervious wall and the mechanical devices merely alter the moisture level of the atmosphere in contact with the interface of the outside wall. This invention is still a different approach tothe moisturetransmission problem, which is more practical in that it concerns alteration of the rate of water transmission through the pervious walls with the result that the transmission of water and water vapor is significantly retarded.

It is an object of this invention to provide a method of retarding the transmission of water and water vapor through a pervious medium. A further object is the provision of a method of retarding water and water vapor transmission throughwood. Another object is to provide a method of treating a pervious medium to minimize moisture-blistering ofv paint, applied to the exposed surface. A further object is to provide a coating system characterized by improved resistance to moisture-blistering. Still further objects will become apparent to those skilled in the art from the detailed description given hereinafter.

These objects are accomplished by treating at least one surface of a rigid pervious medium with a primer composition comprised of an organo-soluble hydrophobic acyclic polymeric titanium mixed ester, hereinafter defined, and applying to the treated surface a continuous coating of film forming material which, in the absence of the surface treatment, will develop moisture-blistering. The polymeric titanium mixed ester consists of a chain of alternating titanium and oxygen atoms having a hydrophobic substituent A in the proportion of at least 0.5 molecular equivalent for each titanium atom, where A is a residual radical of an oxygenated organic compound of 8 to 24 carbon atoms selected from the class consisting of aliphatic monohydric alcohols and aliphatic monocarboxylic acids, minus the hydrogen of the respective functional groups. The remaining titanium linkages are satisfied with OK radicals, where R-is a radical selected from the classy consisting of hydrogen and hydrocarbon radicals, and the hydrocarbon radical being selected from the class consisting of alkyl, cycloalkyl, aryl, and aralkyl radicals having 1 to 8' carbon chain length. The ratio of OI-l radicals to titanium atoms is preferably about 1 or less.

In the preferred embodiment of; the invention, the hydrophobic polymeric titanium mixed ester is a polymeric alkoxytitanium carboxylate such asv is obtained by reacting an organic ester of orthotitanic acid, corresponding to the formula Ti(OR )4 in which R is a hydrocarbon ra-di cal of a monohydric: alcohol containing from 1' to 8 carbon atoms, with an anhydrous aliphatic-monocarboxylic acid, containing from 8 to. 24 carbon. atoms, employing 2 to 4 mols of carboxylic acid per mol of orthotitanate.

Toluene The primer composition was applied to test blocks of wood, Northern white pin measuring 2 x 1 x inches, by complete immersion for a '24 hour period, followed by EXAMPLE 11 Percent by weight Polymeric isopropoxy titanium oleate 10 Toluene 90 drying for 24 hours at room temperature to volatilize the solvent. The treated block and an untreated block cut from the same original board were partially immersed in 100 water at a depth of /3 of the length of the block, With Wood treated with this primer and immersed in water end grain immersed. Under these conditions the unreached a'30% increase in weight in about 163 hours or treated control shows transmission of water to the oppoabout 7 days. site end of the block in a few minutes. These blocks were The same polymeric titanium mixed ester applied at 1% weighed periodically to determine the increase in weight. concentration in toluene was less eifective. In this in- The following table reveals the retarding action of the stance the treated wood registered 30% increase in weight primer toward water absorption and adsorption. in about 21 hours.

TABLE I At 5% concentration, the time required to reach 30% increase in Weight by water absorption was about 35 Increase in weight during water immersion hours.

At concentration the primer was more eifective, Example 1 Untreated with the time required to reach weight increase being at least 224 hours or about 9 days. EXAMPLE III lrninute 0.5 7.5; Percent by weight H gc Polymeric isopropoxy titanium linseed acylate 5 60 minutes. 2.1 22.6 Toluene 95 it; it"? h8g5: 20.2 $5210 25 100 31:2 Wood treated with this primer was equally resistant to i222 water absorption as wood primed with the polymeric 15 13414 isopropoxy titanium oleate of Example II. The following 2,32311011 3&5 141-5 30 table shows comparative data of increase in weight of a The results show that the surface of the treated block wooden block treated and tested as described in Example I.

TABLE II water immersion Time 01 Immersion in Water 5 mins. 1 hr. 1 day 9 days 15 days 24days 30 days 63 days Untreated Control 13.4 26. 5 47.5 71. 8 94. 5 105.1 114 142 1% Polymeric Isopropo v titaniun'i oleate 3. 5 8. 2 33. 2 56. 9 71. 8 85. 2 90. 8 131 5% Polymeric Isopropoxy titanium oleate 3. 3 7. 1 23. 0 52. 4 63. 0 74. 9 82. 7 118. 5 10% Polymeric Isopropoxy titanium oleate 1. 6 4. 2 16. 5 35. 2 42.0 49. 4 57. 7 100. 2 20% Polymeric Isopropoxy titanium oleate 1.5 3. 3 14.5 29. 8 38. 2 40. 2 44. 9 79. 2 1% Polymeric Isopropoxy titanium linseed acylate 6.0 10.0 36. 5 64.0 77.1 92. 2 106.1 144.5 5% Polymeric Isopropoxy titanium linseed acylate 2. 8 5. 3 19. 0 39. 2 47.0 57. 4 70.8 131. 5 10% Polymeric Isopropoxy titanium linseed acylate 2. 6 5.0 17. 2 35. 2 41. 7 50. 2 59. 4 110 20% Polymeric Isopropoxy titanium linseed acylate 2. 3 5. 1 18.3 30.0 34. 9 40. O 44. 4 90. 8

1 Northern white nine 2" x l X is substantially water repellent as indicated by the better than tenfold increase in weight by the control during the first sixty minutes immersion in water in comparison with the treated block. For Water-immersion periods of 24 hours and longer the average ratio of weight increase for the control in comparison with the treated wood was about 4 to 1, indicating a significant retarding effect on water absorption for the polymeric titanium mixed ester.

Table I further indicates that the control absorbed water equal to 30% of its original Weight in about 9 hours. The treated wood reached this concentration of absorbed water in about 1350 hours.

TABLE III Percent gain in weight of wooden block during water immersion A 30% increase in weight due to water absorption is Time of Immersion In Water 1 our 24 Hours recognized as a critical value since it corresponds with Treating Agent.

the amount of water capable of saturating the fiber strucvn tra utyl Tltanate 6.1 17.6

Monomeric Oetylene Glycol Titanite 5. 4 21. 8

ture of the wood. Water in excess of this content 1s free onomeric Tetrastearyl Titanate 5, 4 20,

Monomeric Tetraacetylphenyl 'Iitanate 7.0 26. 2

to move through the capillaries of the wood structure. Monomeric s p pyl t e 13.3 30.6

, Monomeric Tetraoctyl Titanate e. e 20, 0

Hence, in order for moisture-bhstenng to occur, the water Polymeric Isopropoxy Titanium Stearate 2.1 11.0

7 5 H Polymeric Isopmpoxy Titanium Soya Acylate. 3. 0 12. 3

content of the wood must be at least 30%.

Amh-

Polymeric butoxy titanium stearate used, in place of the polymeric isopropoxy titanium carboxylates of Examples I, II and III produced. similar results.

The polymeric titanium mixed ester used in this example corresponds essentially to a dimer containing about two butyl groups and four stearyl groups per molecule which was the product of the reaction of 4.0 parts. of preformed polymeric tetrabutyl orthotitanate and 100 parts of stearyl alcohol involving partial elimination of butyl alcohol.

Results attained with the use of the primer of Example IV were comparable with those observed with the use of polymeric butoxy titanium stearate and similar polymeric alkoxy titanium carboxylates. The results show that the hydrophobic nature of the long carbon chain substituents is effective whether the linkageto the titanium atom is through a carboxyl bond or an alkoxy bond.

The foregoing data show the significant retarding of moisture absorption of wood by treating it with polymeric titanium mixed esters. Practical. tests show that the water absorption data correlate closely with the water trans mission through wood and blister formation on the exposed side of painted wood surfaces In carrying out practical tests, white pine and red cedar boards dressed to /1 x 6 x- 36 inches weer selected as the substrate. Each board was sectioned with one-half to represent the untreated control and the other half. the primed surface. In preparing the primed half, two coats of a polymeric titanium ester solution in toluene, was brushed on the side to be painted. Two coats of titanium dioxide pigmented linseed oil house paint, having a covering power of 500 square 'feet per gallon were applied over the primed surface and the control surface to provide a film thickness of about 5 mils. The panels were aged by vertical south. outdoor exposure for two months and then sampled for testing. A 9 inch section was taken from each end of the panel for evaluation. the panel samples and floated in water for two days. with the unpainted side down to saturate the wood. Thesoaked discs were then placed in avacuum vessel under 30mm Hg pressure for 30 minutes to eliminate entrapped air and then again floated on water for three days. The soaked discs were evaluated foradhesion of the paint by assembling the disc as a diaphragm of an open face pressure bomb. Pressure of an inert gas, such as nitrogen, was applied until the paint film showed signs of initial formation of blisters and the pressure was thereafter increased at 5 pound increments until the degree of blistering advanced. Less than one pound pressure was required to initiate blistering of the paint film over both the untreated or the primed substrate while Wet with water at the paint-wood interface. These results show that priming the wood in accordance with this invention does not enhance the adhesion of the paint film. Still other tests show that the presence of a polymeric titanium mixed ester was not detrimental to adhesion.

It was surprising and unexpected that materials which do not enhance adhesion of the paint film to a substrate would improve moisture-blistering resistance.

A paint film which exhibits moisture-blistering over an untreated wooden substrate will also show moisture-blistering over wood primed in accordance with this invention when sutficient water has been transmitted through the wood. Hence, the mode of preventingblistering r'esides in adequately retarding water transmission. It is immaterial that wood primed in accordance with this invention, on lengthy exposure to water pressure, eventual- Flat discs 3 inches in diameter were cutfrom 1y transmitsanamount of water in excess of the amount required for fiber saturation (30%) because, in less length of time, fluctuation of the humidity of the atmosphere in contact with the wood will cause the moisture in the wood to move out of the wooden structure to approach equilibrium conditions at a water content below that required to cause blistering.

The remaining portion of the weathered test panel was subjected to the following accelerated moisture-blister test. The test panel was subjected to conditions in which the painted side of the panel'was in contact with an atmosphere maintained at a constant temperature of 35 F. and relative humidity of 40%. The unpainted side of th P 1 161 was in contact with an atmosphere maintained at 70 F. temperature. and 70% relative humidity. The panel was examined every other day for 30 days for signs of blistering and rated. A scale of 0 to 10 was used, where 10 representsblister-free condition and 0 represents complete failure with respect to blistering using adopted photographic standards. The test panel portions treated with the polymeric titanium mixed ester compositions of the examples were rated 10. The untreated control portions of the test panels ranged in blister rating from 6.0 to 8.0. at the endof the normal 30 day exposure test.

Wood primed with monomeric tetralkyl titanates, such as tetrabutyl titanate and tetraisopropyl titanate, having no long chain substituents greater than 8 carbon atoms showed the same degree of blisteringasthe untreated coir trol.

Use of polymeric titanium mixed esters and monomeric titanate esters as an additive to the paint composition showed no improvement in the blistering, characteristics of the paint.

The examples show use of toluene and xylol as the volatile carrier for the. polymeric titanium mixed esters. The invention is not limited to these specifically named solvents. Other hydrocarbons, such as petroleum naphthas, mineral spirits, and other volatile solvents and diluents. used in conventional paint formulation may be used. Esters, alcohols and others, either alone or in admixture with hydrocarbons, are also useful vehicles for the polymeric titanium mixed esters. The pertinent requirement for the solvent is that it be substantially anhydrous to minimize hydrolysis.

Primers containing as little as 1% of polymeric titanium mixed ester have been found to be effective. Liquid esters may be used at concentration, but inasmuch as the polymeric titanium mixed esters are generally waxy solids, they are most effectively applied from solution or dispersion at a concentration preferably in the range of 5 to 25 Application of the primer may be by dipping, brushing, spraying, roller coating and other conventional means of applying liquid coating compositions.

If desired, the primer compositions may be modified with adjuvants, such as, e. g. pigments, dyes, fillers and bodying agents, which are compatible and non-reactive with the polymeric titanium mixed esters.

The use of the primer compositions of this invention is primarily in combination with conventional drying oil paints, but the coating superimposed over the primed surface may be alternatively varnishes, lacquers and synthetic resin finishes clear and pigmented, which are conventionally applied to wood subject to outdoor weathering. These latter finishes generally are more resistant to moisture-blistering than conventional oil paint.

While the invention has been illustrated with respect to retardation of moisture-blistering of exterior house paints applied to wood, the invention is also useful in priming other porous construction materials which are normally painted, such as, e. g., various forms of masonry.

Polymeric titanium mixed esters useful in the practice of this invention are those in which the chain of titanium atoms bridged with oxygen linkages have a hydrophobic substituent A in the molecular equivalent proportion of at least 0.5 substituent A and preferably not more than 1.5 for each titanium atom, where substituent A- is a residual radical resulting from elimination of a functional hydrogen atom from a hydrophobic oxygenated organic compound selected from the class consisting of monohydric alcohols and monocarboxylic acids having 8 to 24 carbon atoms, and preferably 12 to 20 carbon atoms. The remaining titanium linkages are satisfied with OR radicals, where R is a radical selected from the class consisting of hydrogen and hydrocarbon radicals, the hydrocarbon radicals being selected from the class consisting of alkyl, cycloalkyl, aryl and aralkyl radicals having no more than 8 carbon atoms. The ratio of OH radicals to titanium atoms is preferably about 1 or less. The hydrocarbon radicals are derived from monohydric alcohols, such as, e. g. methyl, ethyl, propyl, isopropyl, butyl, cycohexyl, 2-ethyl hexyl, octyl, ethoxy ethyl, benzoyl and phenol.

Representative polymeric titanium carboxylates and mixed esters as defined above are illustrated by the following empirical formulae:

1. Polymeric alkoxy titanium carboxylates:

where R is a hydrocarbon radical as defined above, X is a whole number greater than 1; and A is a monocarboxylic acid radical having at least 8 carbon atoms, such as stearic, lauric, oleic, palmitic, ricinoleic, linoleic, myristic, caprylic, capric, nonylic, linseed oil acids, castor oil acids, cocoanut oil acids, soya bean oil acids, tung oil acids, tall oil acids, and fish oil acids.

2. Polymeric alkoxy mixed titanate esters: OR A A R(O-'ii)x-A l where R is a hydrocarbon radical as defined above, X is a whole number greater than 1; and A is the residual radical of a monohydric alcohol of at least 8 carbon atoms minus the hydroxyl hydrogen, such as, for example, stearyl alcohol, lauryl alcohol, and octyl alcohol.

It is desirable that at least one alkoxy substituent per molecule of polymeric titanium mixed ester be the derivative of a readily volatile alcohol. The following theory might be an explanation of how the invention functions, but it is to be understood that the invention is not to be limited by theoretical explanation. It may be that the polymeric titanium ester is chemically attracted to the wood structure by hydrogen bonding between the polymeric titanate and the Wood structure. This chemical bonding of the polymer to the wood structure might orient the polymer such that hydrophobic long carbon chain substituents protrude to repel the water.

Still more complex polymeric titanium ester mixtures represented by mixing the polymeric titanium carboxylates and the polymeric titanate mixed esters are useful in the practice of this invention.

The polymeric titanium carboxylates useful in the practice of this invention are prepared by reacting a monomeric orthotitanate ester having the formula Ti(OR)4 where R is a hydrocarbon radical selected from the group consisting of alkyl, cycloalkyl, aryl and aralkyl, having- 8 no more than 8 carbon atoms, with at least 2 mols of an anhydrous, aliphatic monocarboxylic acid per mol of titanate as disclosed in U. S. Patent 2,621,193.

The polymeric titanium carboxylates may be prepared also by reacting a monomeric orthotitanate ester having the formula Ti(OR)4 with an 8 to 24 carbon atom carboxylic acid in the presence of 1 to 2 mols of water per mol of orthotitanate as disclosed in U. S. Patent 2,621,195.

Still another means of preparing polymeric titanium carboxylates useful in the practice of this invention is by reacting a titanium tetrahalide with an aliphatic monocarboxylic acid of 8 to 24 carbon atoms in the presence of 1 to 2 mols of water per mol of tetrahalide as described in U. S. Patent 2,621,194.

Useful polymeric titanium mixed esters having alkoxy substituents of different carbon chain lengths, but containing no carboxylic acid radicals may be prepared by reacting a preformed polymeric ester of orthotitanic acid derived of lower aliphatic alcohols and phenols having no more than 8 carbon atoms with a monohydric aliphatic alcohol containing more than 8 carbon atoms as described in U. S. Patent 2,614,112.

It will occur to one skilled in the art that the invention may be extended to embodiments other than those specifically disclosed and therefore it is intended that the scope of the invention shall not be so limited except as defined by the appended claims.

I claim:

1. A method of retarding transmission of water and water vapor through porous wood normally pervious to water and water vapor which comprises impregnating pores of said Wood by applying directly to at least one surface of said wood a primer composition comprising a volatile substantially anhydrous organic liquid and as the sole water vapor retardant an acyclic polymeric titanium mixed ester, said ester being a chain of alternating titanium and oxygen atoms with hydrophobic substituent A attached to titanium atoms in the proportion of at least .5 substituent A per titanium atom, where substituent A is a residual radical of an oxygenated organic compound of 8 to 24 carbon atoms selected from the class consisting of aliphatic monocarboxylic acids and aliphatic monohydric alcohols, minus hydrogen of the respective functional groups, the remaining titanium linkages being satisfied with OR radicals, where R is a radical selected from the group consisting of hydrogen and hydrocarbon radicals, the hydrocarbon radical being selected from the group consisting of alkyl, cycloalkyl, aryl and aralkyl radicals having no more than 8 carbon atoms, the ratio of OH radicals being not greater than about one per titanium atom, and applying at least one continuous coat of a water-insoluble film-forming material over the primed surface.

2. The method of claim 1 in which the polymeric tita nium mixed ester is a polymeric alkoxy titanium carboxylate.

3. The method of claim 1 in which the hydrophobic substituent A of the polymeric titanium mixed ester is an alkoxy group having a chain length of 12 to 20 carbon atoms.

4. The method of claim 1 in which the polymeric titanium mixed ester is a polymeric isopropoxy titanium carboxylate.

5. The method of claim 1 in which the polymeric titanium mixed ester is a polymeric butoxy titanium carboxylate.

6. The method of claim 1 in which the polymeric titanium mixed ester is a polymeric isopropoxy titanium stearate.

7. The method of claim 1 in which the polymeric titanium mixed ester is a polymeric alkoxy titanium ester having at least one alkoxy group of not more than 8 carbon atoms and at least one stearyl group per molecule.

8. Painted wood characterized by improved resistance to capillary transmission of water and water vapor, and

moisture-blistering comprising a wooden substrate, at least one surface of which is treated with a titanium-organic primer, and at least one continuous coat of water-insoluble, film forming material superimposed over said primer, said primer being comprised of an acyclic polymeric titanium mixed ester as the sole water and water vapor retardant, said ester being a chain of alternating titanium and oxygen atoms with hydrophobic substituent A attached to titanium atoms in the proportion of at least .5 substituent A per titanium atom, where substitute A is a residual radical of an oxygenated organic compound of 8 to 24 carbon atoms selected from the class consisting of aliphatic monocarboxylic acids and aliphatic monohydric alcohols, minus hydrogen of the respective functional groups, the remaining titanium linkages being satisfied with OR radicals, where R is a radical selected from the group consisting of hydrogen and hydrocarbon radicals, the hydrocarbon radical being selected from the group consisting of alkyl, cycloalkyl, aryl and aralkyl radicals having no more than 8 carbon atoms, and the ratio of OH radicals not exceeding about one per titanium atom.

9. The product of claim 8 in which the organic top coat is a drying oil paint.

10. The product of claim 8 in which the primer is comprised of polymeric alkoxy titanium carboxylate.

11. The product of claim 8 in which the primer is comprised of polymeric isopropoxy titanium stearate.

12. The product of claim 8 in which the primer is comprised of polymeric butoxy titanium stearate.

13. The product of claim 8 in which the primer is comprised of a polymeric alkoxy titanium ester having at least one alkoxy group of not more than 8 carbon atoms and at least one stearyl group per molecule.

References Cited in the file of this patent UNITED STATES PATENTS 2,557,786 Johannson June 19, 1951 2,621,193 Langkarnmerer Dec. 9, 1952 2,621,194 Balthis Dec. 9, 1952 2,643,262 Bostwick June 23, 1953 2,666,772 Boyd Jan. 19, 1954 FOREIGN PATENTS 125,450 Australia Sept. 25, 1947 OTHER REFERENCES Vanderwalker: Wood Finishing, 1944, pp. 246 and 247. 

1. A METHOD OF RETARDING TRANSMISSION OF WATER AND WATER VAPOR THROUGH POROUS WOOD NORMALLY PERVIOUS TO WATER AND WATER VAPOR WHICH COMPRISES IMPREGNATING PORES OF SAID WOOD BY APPLYING DIRECTLY TO AT LEAST ONE SURFACE OF SAID WOOD A PRIMER COMPOSITION COMPRISING A VOLATILE SUBSTANTIALLY ANHYDROUS ORGANIC LIQUID AND AS THE SOLE WATER VAPOR RETARDANT AN ACYCLIC POLYMERIC TITANIUM MIXED ESTER, SAID ESTER BEING A CHAIN OF ALTERNATING TITANIUM AND OXYGEN ATOMS WITH HYDROPHOBIC SUBSTITUENT A ATTACHED TO TITANIUM ATOMS IN THE PROPORTION OF AT LEAST .5 SUBSTITUENT A PER TITANIUM ATOM, WHERE SUBSTITUENT A IS A RESIDUAL RADICAL OF AN OXYGENATED ORGANIC COMPOUND OF 8 TO 24 CARBON ATOMS SELECTED FROM THE CLASS CONSISTING OF ALIPHATIC MONOCARBOXYLIC ACIDS AND ALIPHATIC MONOHYDRIC ALCOHOLS, MINUS HYDROGEN OF THE RESPECTIVE FUNCTIONAL GROUPS, THE REMAINING TITANIUM LINKAGES BEING SATISFIED WITH -OR RADICALS, WHERE R IS A RADICAL SELECTED FROM THE GROUP CONSISTING OF HYDROGEN AND HYDROCARBON RADICALS, THE HYDROCARBON RADICAL BEING SELECTED FROM THE GROUP CONSISTING ALKYL, CYCLOALKYL, ARYL AND ARALKYL RADICALS HAVING NO MORE THAN 8 CARBON ATOMS, THE RATIO OF -OH RADICALS BEING NOT GREATER THAN ABOUT ONE PER TITANIUM ATOM, AND APPLYING AT LEAST ONE CONTINUOUS COAT OF A WATER-INSOLUBLE FILM-FORMING MATERIAL OVER THE PRIMED SURFACE. 